Was there two Hermes?

I listened to Season 7 Episode 6 of Thoth Hermes. Tobias Churton made the claim that Thoth was Hermes before the current Hermes was and can be addressed as Hermes Trismegistus. How do I verify that for myself? I have a similar 2 Eris problem and I also want to verify that.

Hermès used to be a human, he was Hermès Trismegistus. In life he was an incarnation of Thoth.